• Economic and Environmental Geology
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• v.31 no.6
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• pp.485-498
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• 1998

The water-rock interaction and anthropogenic contamination affecting to geochemical composition of shallow and deep groundwaters were investigated in the agricultural area of Myunggok-ri, Kongju. The shallow groundwater is classified into the chemical types of $Ca-HCO_3$ and $Ca-Cl(SO_4)$ and shows weak acid having an average pH 6.2. Deep groundwater shows the uncontaminated composition of the chemical types of $Na-HCO_3$ and Na $(Ca)-HCO_3$ with pH of 8.4~8.8. The grouping approach of chemical data of waters shows the distinguished trend between water composition influenced anthrophogenic input and water composition mainly determined by natural process such as water-rock interaction. The main anthropogenic inputs affecting chemical composition of shallow groundwater are the contaminants such as $K^+$, $NO_3{^-}$, $Cl^-$ having average values of 4.4 mg/l, 22 mg/l, 13.7 mg/l, respectively. The contaminants were probably derived from fertilizer, sweage, septic tank, and stable, etc. The hydrogen and oxygen isotopic compositions indicate that five deep groundwaters were recharged from different altitudes, and that shallow and deep groundwaters were originated from meteoric water. Tritium contents of waters suggest that deep groundwater was recharged before or just after 1950s, and that shallow groundwater is much younger than deep groundwater. The results of this study may serve as a basic data for the future study of shallow groundwater as a drinking water in agricultural area, in Korea.

• Economic and Environmental Geology
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• v.17 no.4
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• pp.289-298
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• 1984

Uraniferous black slates of the Okchon sequence occur in Koesan (northeast) through Miwon-Boun (middle) to the southwest off Taejon (southwest) within the Okchon fold belt. The Uraniferous balck slates in the southwest off Taejon are particularly well developed in Chubu (northeast) and Moksso-ri (middle) areas whereas they are less developed in Jinsan (southwest) area. The uraniferous beds range from less than a meter to 40 meters in thickness and range from less than 0.02% $U_3O_8$ (cut-off-grade) to 0.05% $U_3O_8$ in the southwestern district off Taejon. Electron microprobe analysis of uranium-minerals found in graphitic slate samples enables to estimate their major compositions semi-quantitatively so that uraninite, ferro-uranophane and chlopinite are tentatively identified. Uranium-minerals are closely associated with carbon and metal sulfides. Correlation analysis of trace element concentrations revealed that U and F.C., and U and Mo are lineary correlative respectively and their correlation coefficients are positively high whereas those of U and V, U and Mn, and U and Zr are negatively low, implying that uranium mineralization has been closely related with concentrations of carbon and molybdenum. Stable isotope analyses of pyrite sulfur range widely from +11.5% to -23.3% in ${\delta}^{34}S$ values whereas those of graphite carbon fall within a narrow range between -23.3% and -28.9% in ${\delta}^{13}C$ values. The wide range of ${\delta}^{34}S$ values suggests that the sulfur could be of meteoric origin rather than of igneous source. The narrow range of ${\delta}^{13}C$ values, which are close to those of coal, indicates that the graphite is organic carbon in origin. Therefore, it is concluded that the uranium mineralization in the Okchon sequence took place primarily in sedimentary environment rich in organic matter and sulfide ion, both of which served as the reducing agents to convert soluble uranyl complex to insoluble uranium dioxide.

• Journal of the Korean Society of Food Culture
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• v.14 no.2
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• pp.147-153
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• 1999

This study was conducted to investigate the sanitation status and food waste state from 220 restaurant owners in Taejon area by questionnaires. As a result, the restaurant owners had proper knowledges on the purposes of the good menu system which is to prove public sanitation and to reduce food waste by changing present food service style. According to the restaurant management characteristics study, the subjects recognized highly for the importance of cleanliness(4.6), taste(4.5) where diversity of portion size(3.9), attractiveness(4.0) were low. 86.3% of the subjects mentioned great reductions in food waste after practicing good menu system. Also the subjects recognized the necessity for further researches on this field. After practicing good menu system in restaurant, their food waste was reduced.

• Research in Community and Public Health Nursing
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• v.8 no.2
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• pp.225-236
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• 1997

This study was conducted to investigate the elderly in urban and rural ares. The subjects were selected in a convenient sampling and the total number was 189(Urban : 95, Rur al : 94). The data were collected by one to one interviews in the period of Sep. 1-30, 1995(Koje) and March 15-28, 1997 (Taejon). The study tools for this study were 1) ADL and IADL 2) Self rating scores for health status. The data were analyzed by percentage, T-test, ANOVA, $X^2$ Test, Pearson correlation coefficiency by SPSS pc WIN. 7.0 program. The results were as follows: 1. The self rating score for health status of the elderly in urban area was lower than that of the rural when compared in the same age group. 2. In the comparison of ADL scores between the elderly in urban and rural areas, there was no statistically significant difference. The IADL score of the rural elderly were higher than that of the urban elderly and there was a statistically significant difference. 3. In the comparison of ADL & IADL scores according to the self rating score for health status, there was a statistically significant difference among health status levels.

• Korean Journal of Human Ecology
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• v.8 no.1
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• pp.211-217
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• 1999

To investigate the fitting and its problems related in clothing fit and to get basic data to develop fitted ready-to-wear garment, total 238 subjects were surveyed during the period of May, 1997 in Taejon. The major results were as follows; 1. The results showed that most subjects had purchased ready-to-wear garments in a department store. 2. The fit of ready-to-wear garments is more suitable in the upper wear such as T-shirts and blouse than in lower wear such as skirts and pants. 3. Fitting problems in ready-to-wear garments were identified, including sleeve length, shoulder area. 4. A variety of fitting problems in ready-to-wear garments were showed waistline, thigh girth, sleeve length. 5. There were significant differences between the demographic variables, i.e. marital status and occupation and clothing problems.

• Proceedings of the KIEE Conference
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• 2000.11a
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• pp.232-235
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• 2000

Design and experiments of a nondestructive system to inspect deterioration of ACSR-OC (ACSR Outdoor Cross-linked Polyethylene Insulated Wire usually used in HV overhead distribution lines presented in this paper. ACSR-OC conductor built to pollutants air for a long period would be easily progress to corrode so that it may lead to the reduction of the effective cross section area of conductors. A fault diagnosis system consisting of a solenoid sensor, a constant current source with RF frequency signal processing unit and a motor driver/controller designed and implemented. This instrument can dot the sensor output variation due to deterioration corrosion, continuously. As a result, it was shown such corrosion detector can readily be utilized estimating the diameter change due to deterioration overhead distribution lines and in giving an warning or inform before severe aged conductor lead to fail.

• Journal of Environmental Health Sciences
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• v.25 no.3
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• pp.94-102
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• 1999

To estimate the effects of environmental noise on inhabitants' life in an apartment area at Taejon, noise levels and traffic volume of major roads were measured. 203 housewives were surveyed by questionaires including general factors, noise related factors and three items of life effects: subjective evaluations on the general environment, annoyance, and life disturbance due to environmental noise. At the boundary adjacent to the road with more traffic volume, noise level was higher; according to the time, the amount of noise level was in the morning, in the evening, at noon, and at night in order. Most of boundary noise levels were higher than those of recommended standard environmental noise levels in a residential area. The boundary noise level showed a very significant linear relationship with traffic volume of near roads. Noise level difference in the apartments adjacent to three roads was ranged 2.4~6.7dB between in windows open and close state. The apartments adjacent to 9 lane or 6 lane-road, which were protected by noise prevention wall and 20m or more distance from the roads, showed higher noise level at middle floors and high floors than those of low floors; but the buildings adjacent to 4 lane-road, with no protection, showed higher noise level at low and middle floors than those of high floors. Among 203 housewives, 120(59.1%) participated in this study, and 86(73.2%) of them answered that the most serious environmental noise was traffic noise from near roads. Comparing traffic noise levels with those of before-migration, 67.0% participants found the environmental noise became louder. Fifty eight(49.5%) of the participants wanted noise protection wall and 15(25.9%) of them were willing to charge the fee. Less perception on the present noise comparing to those before-migration, less traffic volume, and lower noise levels in the apartments were related to higher scores of self-evaluation on the environment. Higher susceptibility on the present noise, areas with more traffic volume, higher boundary noise levels, and higher noise levels showed higher scores of annoyance on environmental noise and life disturbance. Considering above all things, it was suggested that traffic noise in this area was the major problem of environmental noise, and its' effect was so serious that inhabitants needed some preventive measures for better life quality.

• Economic and Environmental Geology
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• v.30 no.1
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• pp.51-60
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• 1997

The high radon (Rn222) potentials of soil, groundwater, hotspring and indoor environments in the Taejon city area were delineated by use of an EDA RDA-200 radon detector. The U and Th contents were also analysed using a Multi Channel Analyzer to illustrate the sources of the radon potentials. The average U concentrations in Taejon vary according to the type of granites such as $4.14{\pm}2.36ppm$ in schistose granite (SG), $3.13{\pm}1.70ppm$ in biotite granite (BG) and $3.01{\pm}1.95ppm$ in two mica granite (TG). The U contents in the granites are closely related with the amounts of uraniferous minerals. However, the U contents in the soil are found to be $5.05{\pm}4.75ppm$ in TG, $4.07{\pm}1.69ppm$ in BG and $3.87{\pm}1.91ppm$ in SG which are mainly explained by the different cation exchange capacities (CEC) of the soils from various granites. The levels of soil radon are $552{\pm}656pCi/l$ in SG, in which levels at two locations exceed the level of 1,350 pCi/l established as guideline for follow-up action by the U.S. Environmental Protection Agency (EPA), $443{\pm}284pCi/l$ in TG and $224{\pm}115pCi/l$ in the BG. The soil radon concentrations are found to be proportional to the U content and hardness of the soils. The groundwater radon concentrations in the domestic wells of - 30~-100 m depth show that $6,907{\pm}4,665pCi/l$ in TG, $5,503{\pm}6,551pCi/l$ in SG and $2,104{\pm}1,157pCi/l$ in BG which are positively related with U contents in soils. The radon levels of six groundwater wells in TG and two in SG are greater than guideline for drinking water level, 10,000 pCi/l by EPA (1986). Average radon contents of hotsprings and public bathes in the TG area are $7,071{\pm}1,942pCi/l$ and $1,638{\pm}709pCi/l$, respectively, which are below the EPA standard for remedial action value of the 10,000 pCi/l. The mean indoor radon concentrations of the TG and SG areas are $1.60{\pm}1.20pCi/l$ and $1.60{\pm}0.70pCi/l$, respectively. The elevated indoor radon levels of 5.6 pCi/l and 6.7 pCi/l are found to be particularly in TG area, which exceeds 4 pCi/i guideline, correlating positively with the U contents in the soil and radon concentration in the groundwater.

• Economic and Environmental Geology
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• v.33 no.6
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• pp.505-517
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• 2000

This study was undertaken to provide a drinking water quality on the basis of physicochemical properties. In this study, the 25 samples of supply waters of the Taejon area were sampled twice (February and August in 1999). Hydrochemistry of the supply water belongs to the $Ca^{2＋}$-${HCO_3}^{-1}$ type, whereas the supply water was characterized by the relatively significant enrichment of ${Ca}^{2+}$, ${Na}^{2+}$, ${K}^{2+}$, ${Cl}^{2+}$ ions and heavy metals compared to the original water from the Daecheong lake. Generally, the supply water has a mean values for $10.7^{\circ}C$ of temperature, 6.86 of pH, -12 mV of Eh, 88 ${\mu}S$/cm of EC and 70.379 mg/l of TDS in February, whereas the waters of the same sites in August are a slightly high temperature ($26.1^{\circ}C$), TDS (78.069 mg/l) and extremely high EC (442 ${\mu}S$/cm) value. These values are similar with physicochemical properties of the original lake water depending on the seasonal differences. Results of speciation calculation indicate that potentially toxic ions might exist mainly in the forms of free metal (${Cu}^{2+}$ or ${Zn}^{2+}$) and a small amount of ${CO_3}^{2-}$and ${OH}^{-}$in the supply water. The water seemed to be in equilibrium with kaolinite field of the normal stability diagrams for the natural water. Based on enrichment parameter of the supply water normalized by original lake water composition, the average value of those parameter can be calculated with nearly 1.00, but the those values for Cu＋Zn possible source of decrepit pipe lines are 126.75 in February and 115.63 in August samples. The parameter values varied with sampling sites, however, do not exceed by chemistry of drinking water standard. Solid compounds remained on the membrane filter papers after filtration are adhered to pale yellow or yellowish brown colored dissolved solids and precipitates, which are coated by 0.02 to 0.35 mm thick per 500 ml with colloidal particles of about 1 to 2${\mu}m$ size. The particles are mainly Fe-Cu-Zn compounds and partly detected to Mn and Pb.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 1999.11b
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• pp.155-159
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• 1999

This paper represents analysis of terrestrial DTV field test results over Taejon city area. Thirty three points were selected as measuring points. Signal power, noise power, Segment Error Rate (SER) and equalizer performance was measured. DTV video & audio quality was good over half of test sites. Equalizer could correct signal ghost and improve S/N up to 13.7dB.